SoQtGLWidget Class Reference

The SoQtGLWidget class manages OpenGL contexts. More...

#include <Inventor/Qt/SoQtGLWidget.h>

Inheritance diagram for SoQtGLWidget:

Public Member Functions
SbBool	getAccumulationBuffer (void) const
SbBool	getAlphaChannel (void) const
QWidget *	getGLWidget (void) const
void	getLineWidthLimits (SbVec2f &range, float &granularity)
QWidget *	getNormalWidget (void) const
unsigned long	getOverlayTransparentPixel (void)
QWidget *	getOverlayWidget (void) const
void	getPointSizeLimits (SbVec2f &range, float &granularity)
int	getSampleBuffers (void) const
SbBool	getStencilBuffer (void) const
SbBool	hasNormalGLArea (void) const
SbBool	hasOverlayGLArea (void) const
SbBool	isBorder (void) const
SbBool	isDoubleBuffer (void) const
SbBool	isDrawToFrontBufferEnable (void) const
SbBool	isOverlayRender (void) const
SbBool	isQuadBufferStereo (void) const
SbBool	isStealFocus (void) const
void	setAccumulationBuffer (const SbBool enable)
void	setAlphaChannel (const SbBool enable)
void	setBorder (const SbBool enable)
virtual void	setDoubleBuffer (const SbBool enable)
void	setDrawToFrontBufferEnable (const SbBool enable)
void	setOverlayRender (const SbBool onoff)
void	setQuadBufferStereo (const SbBool enable)
void	setSampleBuffers (const int numsamples)
void	setStealFocus (SbBool enable)
void	setStencilBuffer (const SbBool enable)
Public Member Functions inherited from SoQtComponent
virtual	~SoQtComponent ()
QWidget *	getBaseWidget (void) const
const char *	getClassName (void) const
const char *	getIconTitle (void) const
QWidget *	getParentWidget (void) const
QWidget *	getShellWidget (void) const
SbVec2s	getSize (void) const
const char *	getTitle (void) const
QWidget *	getWidget (void) const
const char *	getWidgetName (void) const
virtual void	hide (void)
SbBool	isFullScreen (void) const
SbBool	isTopLevelShell (void) const
SbBool	isVisible (void)
virtual void	setComponentCursor (const SoQtCursor &cursor)
SbBool	setFullScreen (const SbBool onoff)
void	setIconTitle (const char *const title)
void	setSize (const SbVec2s size)
void	setTitle (const char *const title)
void	setWindowCloseCallback (SoQtComponentCB *const func, void *const user=NULL)
virtual void	show (void)
Public Member Functions inherited from SoQtObject
virtual SoType	getTypeId (void) const =0
SbBool	isOfType (SoType type) const

Protected Member Functions
	SoQtGLWidget (QWidget *const parent=NULL, const char *const name=NULL, const SbBool embed=TRUE, const int glmodes=SO_GL_RGB, const SbBool build=TRUE)
	~SoQtGLWidget ()
QWidget *	buildWidget (QWidget *parent)
float	getGLAspectRatio (void) const
SbVec2s	getGLSize (void) const
float	getGlxAspectRatio (void) const
SbVec2s	getGlxSize (void) const
void	glFlushBuffer (void)
void	glLockNormal (void)
void	glLockOverlay (void)
virtual SbBool	glScheduleRedraw (void)
void	glSwapBuffers (void)
void	glUnlockNormal (void)
void	glUnlockOverlay (void)
virtual void	initGraphic (void)
virtual void	initOverlayGraphic (void)
SbBool	isRGBMode (void)
SbBool	isStereoBuffer (void) const
virtual void	processEvent (QEvent *event)
virtual void	redraw (void)=0
virtual void	redrawOverlay (void)
void	setGLSize (const SbVec2s size)
void	setGlxSize (const SbVec2s size)
void	setStereoBuffer (SbBool flag)
virtual void	sizeChanged (const SbVec2s &size)
virtual void	widgetChanged (QWidget *w)
Protected Member Functions inherited from SoQtComponent
	SoQtComponent (QWidget *const parent=NULL, const char *const name=NULL, const SbBool embed=TRUE)
void	addVisibilityChangeCallback (SoQtComponentVisibilityCB *const func, void *const user=NULL)
virtual void	afterRealizeHook (void)
virtual const char *	getDefaultIconTitle (void) const
virtual const char *	getDefaultTitle (void) const
virtual const char *	getDefaultWidgetName (void) const
void	registerWidget (QWidget *widget)
void	removeVisibilityChangeCallback (SoQtComponentVisibilityCB *const func, void *const user=NULL)
void	setBaseWidget (QWidget *widget)
void	setClassName (const char *const name)
void	unregisterWidget (QWidget *widget)

Protected Attributes
SbBool	drawToFrontBuffer
SbBool	waitForExpose

Additional Inherited Members
Static Public Member Functions inherited from SoQtComponent
static SoQtComponent *	getComponent (QWidget *widget)
static void	initClasses (void)
static void	setWidgetCursor (QWidget *w, const SoQtCursor &cursor)
Static Public Member Functions inherited from SoQtObject
static SoType	getClassTypeId (void)
static void	init (void)
static void	initClass (void)

Detailed Description

The SoQtGLWidget class manages OpenGL contexts.

This is the basic, abstract component class which sets up an OpenGL canvas for its subclasses.

Application programmers will normally not use this class directly, but rather through the interface of either its direct descendent, SoQtRenderArea, or through one of the "rapid application development"-style viewer subclasses.

An important thing to know about embedding SoQtGLWidget derived components into other Qt widgets is that you need to set up "focus proxying" to have events still be sent to the OpenGL canvas widget. This is true for both the SoQtRenderArea as well as all the viewer components (like SoQtExaminerViewer, SoQtPlaneViewer etc).

As an example, if you embed an SoQtExaminerViewer inside a QFrame like this:

QMainWindow * toplevel = new QMainWindow;
QFrame * frame = new QFrame(toplevel);
SoQtExaminerViewer * viewer = new SoQtExaminerViewer(toplevel);

...events from the keyboard will not always automatically be forwarded to the viewer OpenGL canvas. This is the code you need to add in this case:

toplevel->setFocusProxy(viewer->getWidget());

Constructor & Destructor Documentation

SoQtGLWidget()

SoQtGLWidget::SoQtGLWidget ( QWidget *const parent = NULL, const char *const name = NULL, const SbBool embed = TRUE, const int glmodes = SO_GL_RGB, const SbBool build = TRUE )

protected

The constructor is protected, as this is an abstract class to only be used by its subclasses.

~SoQtGLWidget()

SoQtGLWidget::~SoQtGLWidget ( )

protected

Clean up all use of internal resources.

The destructor is protected, as this is an abstract class to only be used by its subclasses.

Member Function Documentation

buildWidget()

QWidget * SoQtGLWidget::buildWidget ( QWidget * parent )

protected

This method builds the component contents in the given parent widget. For subclasses adding new user interface items, this method is typically overridden in the following manner:

QWidget* MyOwnViewer::buildWidget(QWidget* parent)
{
   QWidget* superw = <superclass>::buildWidget(parent);
   // [then move superw within MyOwnViewer framework and add own
   // user interface components]
}

getAccumulationBuffer()

SbBool SoQtGLWidget::getAccumulationBuffer

(

void

)

const

Returns whether the OpenGL accumulation buffer is enabled.

The returned flag will indicate whether or not accumulation buffers are actually present, and not just parrot the input value to SoQtGLWidget::setAccumulationBuffer(). See documentation of that function for more information.

getAlphaChannel()

SbBool SoQtGLWidget::getAlphaChannel

(

void

)

const

Returns whether the alpha channel is enabled for the OpenGL context.

getGLAspectRatio()

float SoQtGLWidget::getGLAspectRatio ( void ) const

protected

Return the aspect ratio of the OpenGL canvas.

getGLSize()

SbVec2s SoQtGLWidget::getGLSize ( void ) const

protected

Return the dimensions of the OpenGL canvas.

getGLWidget()

QWidget * SoQtGLWidget::getGLWidget

(

void

)

const

Returns a pointer to the toolkit-native GL widget.

getGlxAspectRatio()

float SoQtGLWidget::getGlxAspectRatio ( void ) const

inlineprotected

This function has been renamed to the more appropriate getGLAspectRatio.

See also

getGLAspectRatio

getGlxSize()

SbVec2s SoQtGLWidget::getGlxSize ( void ) const

inlineprotected

This function has been renamed to the more appropriate getGLSize.

See also

getGLSize

getLineWidthLimits()

void SoQtGLWidget::getLineWidthLimits	(	SbVec2f &	range,
		float &	granularity )

This function is provided as a convenience for the application programmer to help with acquiring the OpenGL implementation limits for rendering lines.

For robust application code, one needs to consider the range limits when setting the SoDrawStyle::lineWidth field.

getNormalWidget()

QWidget * SoQtGLWidget::getNormalWidget

(

void

)

const

For SoQt, this returns the same widget pointer as that of SoQtGLWidget::getGLWidget().

getOverlayTransparentPixel()

unsigned long SoQtGLWidget::getOverlayTransparentPixel

(

void

)

Returns the overlay transparent pixel.

getOverlayWidget()

QWidget * SoQtGLWidget::getOverlayWidget

(

void

)

const

Returns widget associated with overlay planes, or NULL if no overlay planes are available.

For the Qt toolkit, overlay planes is a feature of the QGLWidget, and not seen at a separate widget entity. So this call will just return the same widget reference as the SoQt::getGLWidget() call (if overlay planes are supported).

Returns widget associated with overlay planes, or NULL if no overlay planes are available.

For the Qt toolkit, overlay planes is a feature of the QGLWidget, and not seen at a separate widget entity. So this call will just return the same widget reference as the SoQt::getGLWidget() call (if overlay planes are supported).

getPointSizeLimits()

void SoQtGLWidget::getPointSizeLimits	(	SbVec2f &	range,
		float &	granularity )

This function is provided as a convenience for the application programmer to help with acquiring the OpenGL implementation limits for rendering points.

For robust application code, one needs to consider the range limits when setting the SoDrawStyle::pointSize field.

getSampleBuffers()

int SoQtGLWidget::getSampleBuffers

(

void

)

const

Returns the number of samples used for multisampling. Returns 1 if multisampling is disabled.

getStencilBuffer()

SbBool SoQtGLWidget::getStencilBuffer

(

void

)

const

Returns whether the OpenGL stencil buffer is enabled.

The returned flag will indicate whether or not stencil buffers are actually present, in the same manner as for SoQtGLWidget::getAccumulationBuffer(). See documentation of SoQtGLWidget::setStencilBuffer().

glFlushBuffer()

void SoQtGLWidget::glFlushBuffer ( void )

protected

Flush the current GL buffer. Simply calls glFlush().

glLockNormal()

void SoQtGLWidget::glLockNormal ( void )

protected

This method calls make-current on the correct context and increases the lock level.

glLockOverlay()

void SoQtGLWidget::glLockOverlay ( void )

protected

This method calls make-current on the correct context and increases the lock level.

glScheduleRedraw()

SbBool SoQtGLWidget::glScheduleRedraw ( void )

protectedvirtual

Will be called whenever scene graph needs to be redrawn. If this method return FALSE, redraw() will be called immediately.

Default method simply returns FALSE. Override this method to schedule a redraw and return TRUE if you're trying to do The Right Thing.

Reimplemented in SoQtRenderArea.

glSwapBuffers()

void SoQtGLWidget::glSwapBuffers ( void )

protected

Swap back buffer to front and vice versa.

glUnlockNormal()

void SoQtGLWidget::glUnlockNormal ( void )

protected

This method decreases the lock level.

glUnlockOverlay()

void SoQtGLWidget::glUnlockOverlay ( void )

protected

This method decreases the lock level.

hasNormalGLArea()

SbBool SoQtGLWidget::hasNormalGLArea

(

void

)

const

Will return TRUE if a normal GL drawing area exists.

hasOverlayGLArea()

SbBool SoQtGLWidget::hasOverlayGLArea

(

void

)

const

Will return TRUE if an overlay GL drawing area exists.

initGraphic()

void SoQtGLWidget::initGraphic ( void )

protectedvirtual

Will be called when GL widget should initialize graphic, after the widget has been created. Default method enabled GL_DEPTH_TEST.

Reimplemented in SoQtRenderArea.

initOverlayGraphic()

void SoQtGLWidget::initOverlayGraphic ( void )

protectedvirtual

Will be called after the overlay widget has been created, and subclasses should override this to initialize overlay stuff.

Default method does nothing.

Reimplemented in SoQtRenderArea.

isBorder()

SbBool SoQtGLWidget::isBorder

(

void

)

const

Returns whether or not there's a border framing the OpenGL canvas.

See also

setBorder()

isDoubleBuffer()

SbBool SoQtGLWidget::isDoubleBuffer

(

void

)

const

Returns the status of the buffer mode.

See also

setDoubleBuffer()

isDrawToFrontBufferEnable()

SbBool SoQtGLWidget::isDrawToFrontBufferEnable

(

void

)

const

See also

setDrawToFrontBufferEnable()

isOverlayRender()

SbBool SoQtGLWidget::isOverlayRender

(

void

)

const

Returns a flag indicating whether or not overplay planes are currently used.

See also

setOverlayRender()

isQuadBufferStereo()

SbBool SoQtGLWidget::isQuadBufferStereo

(

void

)

const

Returns TRUE if quad buffer stereo is enabled for this widget.

isRGBMode()

SbBool SoQtGLWidget::isRGBMode ( void )

protected

Returns TRUE if the normal GL context is in RGBA mode. Return FALSE if color index mode is used.

isStealFocus()

SbBool SoQtGLWidget::isStealFocus

(

void

)

const

Returns whether focus stealing policy is on (TRUE) or off (FALSE).

Default is TRUE.

See also

setStealFocus

Since

SoQt 1.3.0

isStereoBuffer()

SbBool SoQtGLWidget::isStereoBuffer ( void ) const

protected

Returns whether OpenGL stereo buffers are being used.

processEvent()

void SoQtGLWidget::processEvent ( QEvent * anyevent )

protectedvirtual

Any events from the native window system that goes to the OpenGL canvas gets piped through this method.

It is overridden in the subclasses to catch user interaction with the render canvas in the viewers, as well as forwarding relevant events to the scene graph.

Reimplemented in SoQtRenderArea.

redraw()

void SoQtGLWidget::redraw ( void )

protectedpure virtual

This method is invoked when the GL buffer needs to be redrawn.

Implemented in SoQtRenderArea.

redrawOverlay()

void SoQtGLWidget::redrawOverlay ( void )

protectedvirtual

Renders the overlay scene graph. Default method is empty. Subclasses should override this method.

Reimplemented in SoQtRenderArea.

setAccumulationBuffer()

void SoQtGLWidget::setAccumulationBuffer

(

const SbBool

enable

)

Enables/disables the OpenGL accumulation buffer.

For general information about accumulation buffers, confer with your OpenGL reference documentation.

By default, the accumulation buffer will be attempted disabled. Whether or not it will actually be disabled depends on what OpenGL contexts are available on the system. It is perfectly possible that the only usable contexts with regard to the other settings (like double buffering and RGBA mode versus color index mode) causes the context selection to choose an OpenGL format that contains an accumulation buffer, even though it was not requested.

Vice versa, one is not guaranteed to get accumulation buffers even when requested through this function, either because they are not available, or because they are only available in combination with other OpenGL context settings that are not wanted (like single buffers, non-accelerated rendering, etc).

If you try to enable accumulation buffers by using this function, you should therefore in succession use the SoQtGLWidget::getAccumulationBuffer() to query whether or not an accumulation buffer could actually be set up.

See also

SoQtRenderArea::setAntiAliasing()

setAlphaChannel()

void SoQtGLWidget::setAlphaChannel

(

const SbBool

enable

)

Enables/disables the alpha channel for the OpenGL context.

setBorder()

void SoQtGLWidget::setBorder

(

const SbBool

enable

)

Specify whether or not there should be a border framing the OpenGL canvas. The border will be 2 pixels wide.

The default is to display the OpenGL canvas with no border.

See also

isBorder()

setDoubleBuffer()

void SoQtGLWidget::setDoubleBuffer ( const SbBool enable )

virtual

Switch between single and double buffer mode for the OpenGL canvas. The default is to use a single buffer canvas.

See also

isDoubleBuffer()

Reimplemented in SoQtViewer.

setDrawToFrontBufferEnable()

void SoQtGLWidget::setDrawToFrontBufferEnable

(

const SbBool

enable

)

If this is set to TRUE, rendering will happen in the front buffer even if the current rendering mode is double buffered.

setGLSize()

void SoQtGLWidget::setGLSize ( const SbVec2s size )

protected

Sets the size of the GL canvas.

setGlxSize()

void SoQtGLWidget::setGlxSize ( const SbVec2s size )

inlineprotected

This function has been renamed to the more appropriate setGLSize.

See also

setGLSize

setOverlayRender()

void SoQtGLWidget::setOverlayRender

(

const SbBool

onoff

)

Turn on or off the use of overlay planes.

See also

isOverlayRender()

setQuadBufferStereo()

void SoQtGLWidget::setQuadBufferStereo

(

const SbBool

enable

)

Enables or disables OpenGL quad buffer stereo.

setSampleBuffers()

void SoQtGLWidget::setSampleBuffers

(

const int

numsamples

)

Set the number of samples use when enabling multisample buffer contexts. Multisampling will be enabled when numsamples > 1.

setStealFocus()

void SoQtGLWidget::setStealFocus

(

SbBool

enable

)

Sets whether the GL widget should steal keyboard focus when the mouse is over the GL view.

Default is TRUE.

See also

isStealFocus

Since

SoQt 1.3.0

setStencilBuffer()

void SoQtGLWidget::setStencilBuffer

(

const SbBool

enable

)

Enables/disables the OpenGL stencil buffer.

For general information about stencil buffers, confer with your OpenGL reference documentation.

By default, the stencil buffer will be attempted disabled, but the same notes apply for stencil buffers as for accumulation buffers. For an explanation on the issue of stencil and accumulation buffer availability, see the function documentation of SoQtGLWidget::setAccumulationBuffer().

setStereoBuffer()

void SoQtGLWidget::setStereoBuffer ( SbBool flag )

protected

Sets whether OpenGL stereo buffers (quad buffer stereo) should be used.

sizeChanged()

void SoQtGLWidget::sizeChanged ( const SbVec2s & size )

protectedvirtual

Called internally from within the SoQt library when the widget embedded in a component changes its size, which is usually triggered by end-user interaction.

This method is then invoked to notify the component that the size has changed. It is called from the top and all the way down to the bottom, the size being adjusted to take into account extra decorations having been added at each level in the component class hierarchy.

Reimplemented from SoQtComponent.

Reimplemented in SoQtRenderArea, SoQtFullViewer, and SoQtViewer.

widgetChanged()

void SoQtGLWidget::widgetChanged ( QWidget * w )

protectedvirtual

This is the method which gets called whenever we change which OpenGL widget is used.

Should be overridden in subclasses which directly or indirectly store the return value from the SoQtGLWidget::getGLWidget() method.

See also

sizeChanged()

Reimplemented in SoQtRenderArea.

Member Data Documentation

drawToFrontBuffer

SbBool SoQtGLWidget::drawToFrontBuffer

protected

If this is TRUE, rendering will happen in the front buffer even if the current rendering mode is double buffered.

waitForExpose

SbBool SoQtGLWidget::waitForExpose

protected

If this is TRUE, rendering should not be done yet. Upon the first expose event of a newly created OpenGL widget, this variable will be set to FALSE.

---

The documentation for this class was generated from the following files:

• SoQtGLWidget.h
• SoQtGLWidgetCommon.cpp
• SoQtGLWidget.cpp